Oil-shale, one of the leading energy sources under investigation for the production of synthetic fuels, may play a leading role in the energy future of the United States. The primary reason for the growing importance of oil-shale, as well as coal, is the rapid depletion of known petroleum and natural gas reserves. These known reserves are being depleted at a faster rate than the rate of discovering new reserves. As the era of petroleum growth draws to a close, the world's energy mix will have to change. Transition energy sources will be needed as a bridge between petroleum and the potentially unlimited energy sources of the future; such sources being, for example, solar power and nuclear fusion. Owing to their great abundance, coal and oil-shale are perceived as the keystones of such a bridge. Consequently, a great deal of research and development is presently in progress to provide economical ways of converting those energy sources to valuable liquids and gases.
Generally, oil is produced from oil-shale by
Generally, oil is produced from oil-shale by heating the oil-shale in either a fixed or moving bed reactor at a temperature from about 450.degree. C. to 550.degree. C. for a long enough time to convert the organic matter to oil, gas, and residual carbon on spent shale. Although myriad other processes exist for obtaining oil from oil-shale, all of these processes result in a shale-oil which faces severe problems in up-grading owing to a high concentration of nitrogen compounds in the shale-oil; and spent oil-shale having an unacceptable level of nitrogen, sulfur or both. This nitrogen and sulfur could lead to NO.sub.x and SO.sub.x pollutants if the spent oil-shale is combusted for its fuel value.